1. Field of the Invention
The present invention relates to a content delivering system, and more particularly to a content caching and delivering apparatus delivering content, for instance, over a telecommunications network, and to a method therefor.
2. Description of the Background Art
Recently, among content delivering services, video delivering services are increasingly utilized to deliver streams of video data over a telecommunications network. It is said that video traffic of delivering video data occupies the majority of network traffic. It is also well-known that a lot of overlapping video data is flowing in the video traffic. Thus, reduction in the traffic for the overlapping video data would cause the load of video traffic to be reduced, thereby improving the efficiency of traffic on the entire network.
Conventionally, as one solution for reducing the traffic for overlapping video data, there is in-network caching disclosed in Shogo Ando et al., “A Study of In-Network Cache for Redundancy Elimination at Network Edges”, the Institute of Electronics, Information and Communication Engineers (IEICE), Technical Report of IEICE, 2011.
In utilization of the above-mentioned in-network caching, packets passing between any couple of routers are cached and a packet overlapping, or duplicate, with a cached packet is refrained from being transferred between the routers, and instead a substitute packet is sent from the cache of the router on destination side, thereby eliminating the duplication of packets between the routers and thus reducing the video traffic.
In a content delivering way according to the conventional in-network caching, a terminal requests video delivery of a content delivering apparatus via a content caching and delivering server. In view of security, the content delivering apparatus issues a one-time URL (Uniform Resource Locator) as an access destination of content.
The content caching and delivering server transfers the one-time URL from the content delivering apparatus to the requesting terminal, and links and manages the issued one-time URL with an identification (ID) of the content requested.
When the requesting terminal accesses the content delivering apparatus with the one-time URL in order to acquire the content, the content delivering apparatus sends the content associated with the one-time URL to the terminal. At that moment, the content caching and delivering server caches the content from the content delivering apparatus. Subsequently, when another video delivery for the same content as the cached content is requested, the content caching and delivering server deliveries the content it caches.
However, in the above-mentioned conventional content delivering solution, the content delivering apparatus issues a one-time URL each time a content delivery request is raised. In addition, the content caching and delivering server has to link and manage the one-time URLs with content identifications.
Therefore, when different content delivery requests issue to the same content, different response messages, which include respective one-time URLs, are issued in response to content delivery requests. In addition, request messages, which include different one-time URLs, for content delivery from the terminals are different each time, too. There is then a problem that the content caching and delivering server cannot efficiently cache contents to content delivery requests.